This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The main goal of this project is to use Monte Carlo simulations in development of novel fiber optic endoscopes that can simultaneously probe the epithelial and stromal morphology using oblique collection fiber geometry. We will use previously reported scattering properties of human epithelium to predict and to characterize collection efficiency and depth resolution of different probe designs. Design parameters will include source-detector separation;various angles between illumination and collection fibers;fiber diameter;number of collection fibers, etc. We will change optical properties of the epithelium to reflect early cancer development and will optimize probe design to achieve the highest sensitivity to optical changes that are associated with an onset of carcinogenesis. Theoretical predictions will be tested using well defined multi-layered optical phantoms of human epithelium. Successful completion of the project can lead to development of a simple instrument for non-invasive, real time in vivo pre-cancer detection and monitoring via reflectance spectroscopy.